The relative importance of bacterioplankton and phytoplankton in phosphorus uptake in freshwater 1

In several studies of orthophosphate cycling in lakes, most of the phosphorus uptake has been associated with the smallest limnetic particles. The hypothesis that bacteria rather than phytoplankton are responsible for most P uptake in situ was tested in Lake Memphremagog by means of size fractionation of [ super(32)P]orthophosphate uptake, [ super(14)C]glucose uptake (as an indicator of bacterial activity), and both [ super(14)C]bicarbonate uptake and chlorophyll a (as indicators of algal activity). In biweekly samples from May to October, particles